Apparatus for treating materials



APPARATUS FOR TREATING MATERIALS Filed May 8, 1941 s Sheets-Sheet 1mvmok BENJAMIN A. SMITH Arromvavs March 30, 1943. B. A. SMITH APPKRATUSFOR TREATING MATERIALS Filed May 8, 1941 3 Sheets-Sheet 2 I \INVENTOR.BENJAMINASMITH "TIE--7 B March so, 1943. B sM 2,315,022

APPARATUS FOR TREATING MATERIALS Filed May 8, 1941 3 Sheets-Sheet 3INVENTOR. BENJAMIN A.'SM|TH ATTORNEYS v? ,KAMQQW Patentecl Mar. 30, 1943APPARATUS FOR TREATING MATERIALS Benjamin A. Smith, Rocky River, Ohio,assignor to The C. 0. Bartlett & Snow Company Application May 8, 1941,Serial No. 392,479

Claims.

This invention relates, as indicated, to apparatus for the treatment ofmaterials, and this invention particularly relates to apparatus for thepreparation of charges of raw material prior to their introduction intoconventional furnaces, usually of the electric type, employed in themanufacture of metallic alloys.

The manufacture, or more particularly, the smelting of metallic alloys,usually accomplished by a reduction of the ore and frequently thesmelting therewith of a certain amount of scrap metal, is generallycarried on in an electric furnace for the reasons well known in the art.While it is usually necessary and desirable to carry on the finalsmelting operation under the carefully controlled conditions possible inan electric furnace, it is generally not necessary to heat the 'materialfrom its cold state in the electric furnace. If the ingredients orconstituents of the final charge can be heated properly up to atemperature below which the carefully controlled conditions existing inthe electric furnace are not necessary, then hydrocarbon fuels may beemployed to efiect such initial heating with a consequent saving intotal cost.

It is the principal object of my invention to provide apparatus by whichthe above-referred to preliminary heating of the charge constituents maybe advantageously and economically effected.

It is a further object of my invention to provide apparatus of thecharacter described characterized by the fact that the preliminaryheating of the raw materials is effected in a most economical manner andin such a way as to insure that the charges supplied to the electricfurnace for the final heating, reduction or smelting operation may beuniform as to quantity and quality so as to insure maximum efficiency ofoperation of the electric furnace and uniformity of the product producedthereby.

Other objects of my invention will appear as the description proceeds.

To the accomplishment of the. foregoing and related ends, saidinvention, then, consists of the means hereinafter fully described and.particularly pointed out in the claims; the annexed drawings and thefollowing description setting forth in detail certain means and one mode11- lustrating, however, but one of the various ways in which theprinciple of the invention may be used.

In said annexed drawings:

- Fig. 1 is a plan view showing somewhat diagrammatically one form ofapparatus capable of carrying out the principles of my invention;

Fig. 2 is a side elevational View, partially in section, of one of theunits which comprise the combination illustrated in Fig. 1;

Fig. 3 is a transverse sectional view drawn to an enlarged scale of aportion of the apparatus illustrated in Fig. 1 taken on a planesubstantially indicated by the line 3-3;

Fig. 4 is a transverse sectional view of a portion of the structureillustrated in Fig. 3, taken on a plane substantially indicated by theline 4-4; I

Fig. 5 is a fragmentary sectional view of a portion of the apparatusillustrated in Fig. 3, taken on a plane substantially indicated by theline 55;

Fig. 6 is a transverse sectional view similar to Fig. 3 illustrating amodified form of construction; and

, Fig. '7 is an enlarged broken-away sectional view of a part of theapparatus shown in Fig. 6.

Broadly stated, this invention comprises apparatus for the preliminaryheating of charges of raw material such as may be introduced into 'anelectric metallurgical furnace characterized in that separate heatingkilns are employed for such constituents as it is convenient ordesirable to preliminarily heat separately before introduction into thesmelting furnace. Such kilns are preferably sufficiently large incapacity to accommodate a quantity of impounded raw mate rialsubstantially greater, and for most purposes several times the quantityof, individual charges of the particular impounded material.

The impounded material may be heated by some relatively inexpensivehydrocarbon fuel and at a substantially uniform rate so that when theimpounded material, as it is depleted for the purpose of chargingthe'smelting furnace, is replenished at such a rate as to maintainsubstantially constant the temperature of the kiln within which thepreliminary heating is eifected.

Referring now more specifically to the drawings and more especially toFig. l, the arrangement here illustrated is a plan. view of aconventional installation constructed in accordance with the principlesof. my invention. The electric furnace or similar smelting furnace,generally lndicated at I is of course the smelter or melting devicewhich is to be supplied with charges of raw material by the process andapparatus of my invention. The numeral 2 denotes the location of a cranecab, such crane operating, for example, along the line generallyindismelted. For purposes of illustration; only two of such kilns havebeen shown sincethe principles of my invention apply without substantialmodification to an arrangementcornprising a greater number of suchkilns. Throughout-- the ensuing description it will be assumedtherefore, for the purpose of simplifying this description thatthechargefto be suppliedtothe-fu rnace I will consist of twoprimaryconstituents, for con- 'ven'ience referred toa'stheore and lime.- -I'tis assumed; therefore, for I purposes of illustration in describingtheinventiony-thatthefurnace -I Y is a reduction furnace to be supplied:with charges consisting of pre-determ-ined amoutsof oreand lime. For themanufacture of more complex metal alloys it may, of'course;-'- bedesirable, as

above pointed out,'to maintain as separate. units a greater number ofthe charge constituents requiring theuseof--a correspondingly greaternumber of separate kilns. I y It islikewise within the contemplation ofmy invention'toemploy a single pre-heating kiln into which maybeintroduced a mixture of all of the ingredients andin the properproportions *re- U =quired for the charge tothe'smelter. This-may *benecessary'anddesirable wherethe natureof the charging materials is suchthat they-may be advantageously or desirably pie-heated while mixedtogetherm l Each of-'=the kilns-comprises a substantially :cylindricalrefractory lined unit generally indicated at e 6,- provided withcircunirerentially extended supporting rings] which" ride on spacedrollers 8,- all thisbeing} of eourse, wel1 recognized structural designfor the supportof kilns of this character. -Each kiln. will beprovidedwith an annular-drivinggear 9 which will be in mesh .with adriivng pinion and its asso'ciated speedreduc- 'tion-mechanismanddriving-motor, not shown. These last-named elements have. beenomittedfrom the illustration-in order .toclarifythe drawings. It'will-b noted,however, .thatthe driving means forpthe kilns 6will be..capable ofselectively driving eachkiln in opposite directions. Each kilnmay beprovided with a feed. hopper l containing th cold raw material which maybe 'fed theretosbyany-suitable means ;such. as k a screw conveyor,generallyindicatedat:H. The hopper H] may, of course-be supplied withraw material-from a bin, generally indicated at 12, and buckets 'or carssuch :as I3' may, of-course,

be employed for the purpose. of. conveying the.

raw material from the bin'tosthe hoppersnIt .is, of. course, within the'contemplation of myinventionto variously arrange the supply ofurawmaterialso as to' maintain in .the hopper. I0 an adequate quantityof thesametobe fed into the;

; kiln Bbythe feedingdevice 1 Li If. desired, the feeding *device,llandtits associated hopper. IE! maybe moved on a platform. I 4 which,mounted on -rollers, maybe moved to and rromithei feed- Working parts,and if desired, the feeding device, generally indicated at Il, may bemoved into feeding relation with the kiln 6 during only such intervalsas it is necessary in order to keep the 5 kiln 6 supplied with thenecessary quantity of impounded material to be heated in preparation forthe charge. In such case the opening through which the material is fedto the kiln 6 may be closed by some removable device which 10 wouldassist in conserving the heat within the kiln 6.

At the opposite end of the kiln S from the feedingdevice His ahydrocarbon fuel burner generally indicated at! 5 and it is within thecontemplation of'myinvention to employ any suitable fuel in such burner,such as, for example, gas, oil or-powdered coal. This burner heats thematerial internally or directly.

The stack opening from the kiln 6 will pref- -erably be. in the sameendwith the feedingopening, for example, thestackopening may be concentricwithmhe feeding opening, in which case .thefluctpr flue. l6;may,extenddownwardly and lead.:to the main stack for theplant.

5 1 Each :kiln 6 .will be, at some, convenient location preferablyadjacent the-send oe upi d b t hydrocarbonburner, provided with adischarge ring, .generally indicated at l1 the construction anda modeof. operation of which may be more readily determined by havingreference to Figs.

..Refe11fing n0w.-t0-1E s-.. ,-t e en er er he ye the kiln 6. isindicated by theline l 8. .Within the cutershell.tneidlnsspfeceu s pro iw e refractorylining which extends inwardly. to the n I fil sa est;shown i .-r, r g d, i a

. circumferentially ex tending groove on the inner p ip ery e iih s reirq rn i i e e P erality; ofco mplementary v segmental members,

I generally nd c ted. at 2,"- lTb S Segmental me berswill be of somesuitable high-temperature- .re siente lpren se s e t l rectangular inshape with a semif-cyiirrdrical shaped. topfportion 20' eachprovidingashort circumferentiallyflextending laterally restrictedpassage for, the flow ofIjrnaterial fromftheintrior, of, the kiln to theoutsidethero f, showniinFigthe level I9 of the'jr'efractdry'li'ningfextendsonly to the top of the parallel sidewalls of the units20. The top 29 is .rnade se mi-cylindrical in shape in order to impartstrength thereto for preventing buckling of'the same after beingheated.One end of each of these ,s'eg'rnerrtal uhits Z'Q is provided on itsinner face with an opening 2| and the opposite "endsrdf these segmentalare respectively "provided with butwardly extending throats 22.

The several segmental units are provided with circu'mferen'tiallyextending fingers 23 which, when the several units a'reass embled in themanner illustrated in Figs ii and'at their outer ends bolted to theshell-of the kiln fi will lock and these'segmentalunitsagainstdisplacmentr The V casing 24 around the kilnj in thecircumferential area occupiedby the segmental units 20 is for thepi'irpose cf collecting the material discharged fromithe'kilmand asuitable spout such as 25 may be'provide'd to-ca'rry the dischargedmaterialinto I a car or bucket26 which-will-be supported forconven'ienc'e'on a weighing scale platform ZLby which the quantity. (ifmaterial iiischargedfona. particular charge may'beTaccuratelydetermined.

It will be observed that when the kiln rotates in the directionindicated by jthearrow 28;.in.Fig.

ing openingin theikiln 6, This arrangemehtperig. -.3 the.materia.lwithinsthelkilnwill be scooped up v mits ready inspection and repair ofthe various through the openings 2| by the segmental members 2B and aseaclrsegmental member moves to the lowermost position the contents ofthe passage through such member will be discharged into the spout 25.If, however, the kiln is rotated in a direction opposite to that of thearrow 28 the material will be prevented from flowing out through thesegmental members and the material which falls into the openings 2! willdrop back into the kiln upon movement of such openings to the top of thekiln.

In the operation of the apparatuses above described in carrying out theprinciples of my invention, the ore and lime, for example, shall go tomake up the component parts of the charge for the furnace which will beintroduced into the respective kilns 3 and 5. A sufficient quantity ofraw material will be maintained in each kiln at all times so as to morethan supply the requirements for a single chargefor the furnace I. Infact, it will be found desirable in certain instances to impound enoughmaterial in each kiln to supply the requirements of several individualcharges. Thus, a residual charge of hot material is left in each kiln atall times. When heated material is wanted for the furnace charge thekiln, normally rotated in such a direction as to retain the materialtherein and to agitate the same so as to insure its being uniformlyheated, will be stopped and rotated in the opposite direction. This willresult in a discharge of the heated material from the kiln so reversed,and the discharged material will flow into the car 26 where it can beweighed and the rotation of the kiln in the discharging directionstopped when the desired amount of material has been withdrawn. The car23 will preferably be refractory lined, covered and thermally insulatedto preserve the'heat of the material therein during the time when thecar is transferred by means of the crane or otherwise over to thefurnace and its contents charged into the furnace. It will be observedthat the discharge point in the kiln is substantially removed from thecharging point, and if a sufficient quantity of raw material isimpounded in the kiln it may be entirely feasible to feed the rawmaterial into the kiln at a continuous uniform rate. Thus it is feasiblefor certain types of material, and where the impounded quantity of rawmaterial is great enough, to continue the feeding of the cold materialinto the kiln simultaneously with the withdrawal of hot materialtherefrom. For certain types of material it may be found desirable tointerrupt the feeding of cold material into the kiln for an intervalshortly prior to the time when a charge is to be withdrawn from thekiln.

It will be observed from the foregoing description that I have providedapparatus for preliminarily heating the charges for metallurgicalfurnaces characterized by the fact that this preliminary heating of theraw material may be carried on in a substantially continuous manner soas to utilize to the fullest extent the heat of the preliminary heatingmedium. Furthermore this process insures the necessary supply at alltimes of the components of the charge for the furnace and at uniformconditions particularly with respect to temperature; the preliminaryheating being accomplished by the use of relatively inexpensive fuel,the process comprising my invention materially reduces the total cost ofthe smelting operation.

It is further frequently found desirable to accomplish the preliminaryheating in an oxidizing atmosphere to the end that free carbonaceousmaterials contained in the ingredients entering into the furnace charge,may be fully oxidized and converted to gases which pass out of thepreheater apparatus thereby greatly assisting the control of carbon inthe alloy'subsequently produced by the furnace.

In Figures 6 and '7, there is shown a modified form of construction ofthe units 20. In this showing like numerals have been used to designatelike parts and it will be understood that the manner of operation ofsuch modified construction of the units 20 is essentially the same asdescribed for the construction shown in Figure 3. The dilference in theshowing of Figures 6 and 7 lies mainly in a change in the shape of thethroats 22 and in a change in the interlocking connection of the variousunits 20 by which the fingers 23 of Figure 3 are eliminated. The throats22, instead of being inclined as shown in Figure 3, extend in a radialdirection with respect to the kiln. In place of the interlocking fingers23, each unit is provided with a transversely extending ledge 38 at theend thereofadjacent the discharge opening 22 which is adapted tointerlockingly engage with the top 3| of an endwall 32 of the nextadjacent unit 20 as best shown in Fig. 7. Each of the ledges 30 definesthe upper edge of an opening in one of the units 20 in which the endwall32 of the next adjacent unit 20 is receivable. In this manner, eachendwall 32 functions as an endwall for each of adjacent units and iseifective to separate the circumferentially extending passages 33 ofadjacent units 20 from each other. In assembling the units 20, theflanges 34 of the throats 22 are bolted to the liner 18 to secure oneend of each unit 20 in position as shown in Figure '7, the other end ofeach unit 20 being held in position by the interlocking engagement ofthe ledge 30 with the top 31 of the walls 32. In this manner, the ledge30 is made to serve the same purpose as the fingers 23 of Figure 3.

Each of the units 20 may be provided with a transversely extending ledge35 adjacent the openings 22 as shown in Figures 6 and 7, for restrictingpassage of material out of the passages 33 when the kiln is rotated in aclockwise direction. When th kiln is not discharging and is rotatingclockwise, material will fall into the openings 2| as such openings moveunder the material within the kiln. The ledges 35 will be foundeifective to prevent such material from dribbling and falling out theopenings 22 as such openings approach their lowermost position in aclockwise direction. A rib or ledge 36 may be provided, as shown inFigures 6 and '7, adjacent the opening 2| for the purpose of reinforcingthat portion 20' of the units 20 which defines the opening 2!.

This application is a continuation in part of my co-pending applicationSerial No. 159,140 which has now matured into Patent No. 2,241,429.

Other modes of applying the principle of my invention may be employedinstead of the one explained, change being made as regards the meansherein disclosed, provided those stated by any of the following claimsor their equivalent be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In apparatus of the character described, a rotatably supportedcylindrical kiln, and means operable upon rotation of said kiln in onedirection to discharge material therefrom, and operable upon rotation ofsaid kiln in an opposite direction to retain material therein,comprising, a plurality of like members arranged circumferenin asegmental I annular passage" and having an I said interlocking meanscotfi iri'ss finger members is'preiiiaed 'wrthen opening, thend or thenext 'eajaeent uiiit hav'i'ngan end wan receivable in said opening forinterleckmg said units in posibion, "sa'idkiidfill being effective toseparate "djbicht segmental annular passages "from each ether. 4 I

"BENJAMIN A. SMITH.

